package com.kingyun.gpsinspection.purificationservice.common.utils;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.SecureRandom;

/**
 * 编码工具类
 * 1.将byte[]转为各种进制的字符串
 * 2.base 64 encode
 * 3.base 64 decode
 * 4.获取byte[]的md5值
 * 5.获取字符串md5值
 * 6.结合base64实现md5加密
 * 7.AES加密
 * 8.AES加密为base 64 code
 * 9.AES解密
 * 10.将base 64 code AES解密
 * Created by yangcs on 2017/1/9.
 */
public class AesUtil {
    //密钥
    public static final String AES_KEY = "git.cqhilink.com";
    private static Logger logger = LoggerFactory.getLogger(AesUtil.class);
    //AESCrypt-ObjC uses blank IV (not the best security, but the aim here is compatibility)
    private static final byte[] ivBytes = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
    /**
     * 将byte[]转为各种进制的字符串
     * @param bytes byte[]
     * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
     * @return 转换后的字符串
     */
    public static String binary(byte[] bytes, int radix){
        return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
    }

    /**
     * base 64 encode
     * @param bytes 待编码的byte[]
     * @return 编码后的base 64 code
     */
    public static String base64Encode(byte[] bytes){
        return new BASE64Encoder().encode(bytes);
    }

    /**
     * base 64 decode
     * @param base64Code 待解码的base 64 code
     * @return 解码后的byte[]
     * @throws Exception
     */
    public static byte[] base64Decode(String base64Code) throws Exception{
        return StringUtils.isBlank(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
    }

    /**
     * 获取byte[]的md5值
     * @param bytes byte[]
     * @return md5
     * @throws Exception
     */
    public static byte[] md5(byte[] bytes) throws Exception {
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(bytes);

        return md.digest();
    }

    /**
     * 获取字符串md5值
     * @param msg
     * @return md5
     * @throws Exception
     */
    public static byte[] md5(String msg) throws Exception {
        return StringUtils.isBlank(msg) ? null : md5(msg.getBytes());
    }

    /**
     * 结合base64实现md5加密
     * @param msg 待加密字符串
     * @return 获取md5后转为base64
     * @throws Exception
     */
    public static String md5Encrypt(String msg) throws Exception{
        return StringUtils.isBlank(msg) ? null : base64Encode(md5(msg));
    }

    /**
     * AES加密
     * @param obj 待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的byte[]
     * @throws Exception
     */
    public static byte[] aesEncryptToBytes(JSONObject obj, String encryptKey) throws Exception {
        String content = JSON.toJSONString(obj);
        logger.info("待加密json字符串:"+content);
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128, new SecureRandom(encryptKey.getBytes()));

        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));

        return cipher.doFinal(content.getBytes("utf-8"));
    }

    /**
     * AES加密为base 64 code
     * @param obj 待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的base 64 code
     * @throws Exception
     */
    public static String aesEncrypt(JSONObject obj, String encryptKey) throws Exception {
        return base64Encode(aesEncryptToBytes(obj, encryptKey)).replace("+","%2B");
    }

    /**
     * AES解密
     * @param encryptBytes 待解密的byte[]
     * @param decryptKey 解密密钥
     * @return 解密后的String
     * @throws Exception
     */
    public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128, new SecureRandom(decryptKey.getBytes()));

        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
        byte[] decryptBytes = cipher.doFinal(encryptBytes);

        return new String(decryptBytes,"UTF-8");
    }

    /**
     * 将base 64 code AES解密
     * @param encryptStr 待解密的base 64 code
     * @param decryptKey 解密密钥
     * @return 解密后的string
     * @throws Exception
     */
    public static JSONObject aesDecrypt(String encryptStr, String decryptKey) throws Exception {
        logger.info("待解密的内容:"+encryptStr);
        //待解密的内容为空返回null
        if(StringUtils.isBlank(encryptStr)){
            return null;
        }else{
            //解密后的字符串
            String content = aesDecryptByBytes(base64Decode(encryptStr.replace("%2B","+")), decryptKey);
            logger.info("解密后的内容:"+content);
            try {
                JSONObject obj = JSON.parseObject(content);
                return obj;
            } catch (Exception e) {
                return null;
            }
        }
    }
    //测试方法
    public static void main(String[] args) throws Exception{
        JSONObject obj = new JSONObject();
        obj.put("loginName","12345678");
        obj.put("password","12345678");
        //obj.put("password1","admin");
        //obj.put("password2","admin");
        //obj.put("timestamp",System.currentTimeMillis());
        String key = aesEncrypt(obj,AES_KEY);
        System.out.println("加密之后："+key);
        System.out.println("解密之后："+JSON.toJSONString(aesDecrypt(key,AES_KEY)));


        //System.out.println(sendPost("http://192.168.0.83:8080/facade/mobileoffice/usecar/findbycont.htm","params="+key));
    }

}
